Edited to fix links.
We just made the one with the drapery motor and I
love it! We bought the drapery motor online - with shipping I think it was around $90 (after much searching, I finally found the place we bought it from
http://www.discounthomeautomation.c...oduct_id=4897&session_id=0,0&search_id=522881 ), but the investment was worth it to me. Would you pay someone $1 a day to get up and let the chooks out for you? Yes? Then it's paid for itself in 3 months. That's how I look at it anyway.
Here's a link for the directions that we used.
http://www.buildeazy.com/photo-chicken-coop-beatarticle.html It really was a piece of cake. Just mount on the wall, run the rope around the pulley type thingy (isn't that the technical term??), attach one end of the rope to the door and one to a counterweight (we used a brass hose connector - male and female snapped together weighs in at about 100g). Presto. You've got yourself a door opener. We sprung for a pricey timer
http://www.amazon.com/gp/product/B001KBZUMG/ref=oss_product so that we could have one that would adjust itself as the days got longer and shorter. This one was $23, but if you're not quite as scatterbrained as I am, any old timer will do. Using the timer we bought, I've set it up to open at dawn and close at 9pm. It's dark here by 7, so I'm hoping all the stragglers will be resting peacefully by 9 for those evenings when I'm not home to do a headcount. If the timer had a "dusk plus..." function, it would have been perfect. I'd never have to reset it. This way I won't have to reset it all that often.
We don't even have our chickens yet - this weekend is D-Day - but I'm already psyched about the door. I couldn't stop playing with it after we put it together. Open Closed Open Closed - cat in - cat out - cat in - cat out... you get the picture.
Edited to fix links.
Hens go broody when you don’t want them to… and won’t go broody when you do. 
